Biology Words

179 words relating to Biology

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definitions & notes only words
  1. abdomen
    the region of the body between the thorax and the pelvis
  2. abiogenesis
    a hypothetical organic phenomenon by which living organisms are created from nonliving matter
  3. absorption
    a process in which one substance permeates another
  4. activation energy
    the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur
  5. active transport
    transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient; requires an expenditure of energy
  6. allele
    any of the forms of a gene that can occupy the same locus
  7. alternation of generations
    the alternation of two or more different forms in the life cycle of a plant or animal
  8. anabolism
    the synthesis in living organisms of more complex substances (e.g., living tissue) from simpler ones together with the storage of energy
  9. antibiotic
    a substance used to kill microorganisms and cure infections
  10. antigen
    any substance that stimulates an immune response in the body
  11. appendicular skeleton
    the part of the skeleton that includes the pectoral girdle and the pelvic girdle and the upper and lower limbs
  12. asexual reproduction
    reproduction without the fusion of gametes
  13. atrium
    a chamber connected to other chambers or passageways
  14. axial skeleton
    the part of the skeleton that includes the skull and spinal column and sternum and ribs
  15. bilateral symmetry
    the property of being symmetrical about a vertical plane
  16. bile
    a digestive juice secreted by the liver
  17. biomass
    the total amount of living matter in a given unit area
  18. biome
    major ecological community with distinct climate and flora
  19. biosynthesis
    production of a chemical compound by a living organism
  20. bivalve
    marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together
  21. bone marrow
    the fatty network of connective tissue that fills the cavities of bones
  22. botany
    the branch of biology that studies plants
  23. catabolism
    breakdown in living organisms of more complex substances into simpler ones together with release of energy
  24. catalyst
    substance that initiates or accelerates a chemical reaction
  25. cell wall
    a rigid layer of polysaccharides enclosing a plant membrane
  26. cellulose
    a polysaccharide that is the chief constituent of all plant tissues and fibers
  27. centromere
    a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape
  28. cerebellum
    a major division of the vertebrate brain
  29. cerebrum
    anterior part of the brain consisting of two hemispheres
  30. chemical change
    process determined by substances' composition and structure
  31. chitin
    component of arthropods' exoskeletons and bodies of fungi
  32. chlorophyll
    any of green pigments found in photosynthetic organisms
  33. chloroplast
    organelle in which photosynthesis takes place
  34. chromatin
    the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins; during mitotic division it condenses into chromosomes
  35. chromosome
    a threadlike strand of DNA that carries genes
  36. circulatory system
    the organs and tissues involved in circulating blood and lymph through the body
  37. codon
    a specific sequence of three adjacent nucleotides on a strand of DNA or RNA that specifies the genetic code information for synthesizing a particular amino acid
  38. cohesion
    the state of sticking together
  39. commensalism
    when one organism benefits from another without damaging it
  40. community
    a group of people living in a particular local area
  41. compound eye
    in insects and some crustaceans: composed of many light-sensitive elements each forming a portion of an image
  42. concentration
    the spatial property of being crowded together
  43. conjugation
    the state of being joined together
  44. cotyledon
    embryonic leaf in seed-bearing plants
  45. cytology
    the branch of biology that studies the structure and function of cells
  46. cytolysis
    pathological breakdown of cells by the destruction of their outer membrane
  47. cytoplasm
    the substance inside a cell, not including the nucleus
  48. cytoskeleton
    a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and coherence
  49. deciduous plant
    a plant having foliage that is shed annually at the end of the growing season
  50. diffusion
    the act of dispersing something
  51. digestion
    the process by which the body breaks down food
  52. dihybrid cross
    hybridization using two traits with two alleles each
  53. dominant allele
    an allele that produces the same phenotype whether its paired allele is identical or different
  54. ecology
    the environment as it relates to living organisms
  55. ecosystem
    organisms interacting with their physical environment
  56. ectoplasm
    the outer granule-free layer of cytoplasm
  57. ectothermic
    of animals except birds and mammals
  58. element
    a substance that cannot be separated into simpler substances
  59. endoplasm
    the inner portion of the gelatinous liquid inside a cell
  60. endoskeleton
    the internal skeleton; bony and cartilaginous structure
  61. endospore
    a small asexual spore that develops inside the cell of some bacteria and algae
  62. endothermic
    occurring or formed with absorption of heat
  63. epidermis
    the outer layer of skin covering the body surface
  64. epithelium
    membranous tissue covering internal organs and other internal surfaces of the body
  65. excretion
    the bodily process of discharging waste matter
  66. exoskeleton
    the exterior protective or supporting structure or shell of many animals (especially invertebrates) including bony or horny parts such as nails or scales or hoofs
  67. eyespot
    an eyelike marking
  68. fermentation
    breaking down an organic substance, as sugar into alcohol
  69. flagellate
    whip or scourge; punish as if by whipping
  70. foot
    the pedal extremity of vertebrates other than human beings
  71. fruit
    the ripened reproductive body of a seed plant
  72. gemmule
    the physically discrete element that Darwin proposed as responsible for heredity
  73. gene
    part of DNA controlling physical characteristics and growth
  74. genetics
    the study of heredity and variation in organisms
  75. genotype
    the genetic makeup of a particular organism
  76. gestation
    the period during which an embryo develops
  77. gonad
    a gland in which gametes (sex cells) are produced
  78. greenhouse effect
    warming when solar radiation is trapped by the atmosphere
  79. haustorium
    a root-like attachment in parasitic plants that penetrates and obtains food from the host
  80. hermaphroditic
    of animal or plant
  81. hibernation
    the resting state in which some animals pass the winter
  82. holdfast
    restraint that attaches to something or holds something in place
  83. homeostasis
    metabolic equilibrium maintained by biological mechanisms
  84. hydrogen bond
    a chemical bond consisting of a hydrogen atom between two electronegative atoms (e.g., oxygen or nitrogen) with one side be a covalent bond and the other being an ionic bond
  85. hydrolysis
    a chemical reaction in which water reacts with a compound to produce other compounds; involves the splitting of a bond and the addition of the hydrogen cation and the hydroxide anion from the water
  86. hydrophobic
    lacking affinity for water
  87. hypha
    any of the threadlike filaments forming the mycelium of a fungus
  88. hypothesis
    a tentative insight that is not yet verified or tested
  89. inheritance
    hereditary succession to a title or an office or property
  90. isotonic solution
    a solution having the same osmotic pressure as blood
  91. karyotype
    the appearance of the chromosomal makeup of a somatic cell in an individual or species (including the number and arrangement and size and structure of the chromosomes)
  92. loam
    a rich soil consisting of sand, clay and organic materials
  93. lysosome
    a membrane-bound organelle containing digestive enzymes
  94. macroevolution
    evolution on a large scale extending over geologic era and resulting in the formation of new taxonomic groups
  95. mantle
    a sleeveless garment like a cloak but shorter
  96. matter
    that which has mass and occupies space
  97. medulla oblongata
    lower or hindmost part of the brain
  98. medusa
    one of two forms that coelenterates take: it is the free-swimming sexual phase in the life cycle of a coelenterate; in this phase it has a gelatinous umbrella-shaped body and tentacles
  99. meiosis
    cell division that produces reproductive cells
  100. membrane
    a sheet of tissue that lines or connects organs or cells
  101. mesenchyme
    mesodermal tissue that forms connective tissue and blood and smooth muscles
  102. messenger RNA
    the template for protein synthesis
  103. metabolism
    the organic processes that are necessary for life
  104. microevolution
    evolution resulting from small specific genetic changes that can lead to a new subspecies
  105. mitosis
    the process by which a cell divides into two smaller cells
  106. model
    a representation of something, often on a smaller scale
  107. molt
    cast off hair, skin, horn, or feathers
  108. monohybrid cross
    hybridization using a single trait with two alleles
  109. mother cell
    cell from which another cell of an organism develops
  110. mutation
    a change or alteration in form or qualities
  111. mutualism
    the relation between two organisms that benefit each other
  112. mycelium
    the vegetative part of a fungus consisting of a mass of branching threadlike hyphae
  113. nervous system
    the sensory and control apparatus consisting of a network of nerve cells
  114. neurotoxin
    any toxin that affects neural tissues
  115. notochord
    a flexible rodlike structure that forms the supporting axis of the body in the lowest chordates and lowest vertebrates and in embryos of higher vertebrates
  116. nucleus
    a part of the cell responsible for growth and reproduction
  117. osmosis
    diffusion of molecules through a semipermeable membrane
  118. paleontology
    the earth science that studies fossil organisms
  119. parasite
    an animal or plant that lives in or on a host
  120. parasitism
    when one organism benefits from another by causing damage
  121. passive transport
    transport of a substance across a cell membrane by diffusion
  122. pathogen
    any disease-producing agent
  123. pedigree
    the ancestry or lineage of an individual
  124. pellicle
    thin protective membrane in some protozoa
  125. peptide bond
    the primary linkage of all protein structures
  126. phagocytosis
    process in which phagocytes engulf and digest microorganisms and cellular debris; an important defense against infection
  127. phase
    any distinct time period in a sequence of events
  128. phenotype
    observable characteristics produced by genes and environment
  129. phloem
    plant tissue that conducts synthesized food substances
  130. phospholipid
    any of various compounds composed of fatty acids and phosphoric acid and a nitrogenous base; an important constituent of membranes
  131. photosynthesis
    formation of compounds in plants aided by radiant energy
  132. phototropism
    an organism's orienting response to light
  133. physical change
    a change from one state (solid or liquid or gas) to another without a change in chemical composition
  134. physiology
    the science dealing with the functioning of organisms
  135. phytoplankton
    photosynthetic or plant constituent of plankton
  136. placenta
    the vascular structure in the uterus of most mammals providing oxygen and nutrients for and transferring wastes from the developing fetus
  137. plankton
    aggregate of small organisms that float or drift in water
  138. plasma membrane
    a thin membrane enclosing the cytoplasm of a cell
  139. plasmid
    a small cellular inclusion consisting of a ring of DNA that is not in a chromosome but is capable of autonomous replication
  140. pollen
    fine spores produced by flowers to fertilize other flowers
  141. pollination
    transfer of the fine spores that contain male gametes
  142. polyp
    a small vascular growth on the surface of a mucous membrane
  143. population
    the people who inhabit a territory or state
  144. pseudopod
    temporary outgrowth of a cell used for locomotion or feeding
  145. radial symmetry
    the property of symmetry about an axis
  146. recessive allele
    an allele that produces its characteristic phenotype only when its paired allele is identical
  147. regeneration
    the act of forming again; renewing and reconstituting
  148. reproduction
    the act of making copies
  149. respiration
    a single complete act of breathing in and out
  150. saprophyte
    an organism that feeds on dead organic matter especially a fungus or bacterium
  151. secretion
    the organic process of releasing some substance
  152. seed
    small, hard part of a plant from which a new plant can grow
  153. semipermeable membrane
    a membrane (as a cell membrane) that allows some molecules to pass through but not others
  154. sexual reproduction
    reproduction involving the union or fusion of a male and a female gamete
  155. shell
    the material that forms the hard outer covering of many animals
  156. simple eye
    an eye having a single lens
  157. species
    taxonomic group whose members can interbreed
  158. spore
    a small usually single-celled asexual reproductive body produced by many nonflowering plants and fungi and some bacteria and protozoans and that are capable of developing into a new individual without sexual fusion
  159. sporophore
    a spore-bearing branch or organ: the part of the thallus of a sporophyte that develops spores; in ferns and mosses and liverworts is practically equivalent to the sporophyte
  160. stolon
    a horizontal branch from the base of plant that produces new plants from buds at its tips
  161. symbiosis
    the relation between two interdependent species of organisms
  162. taxonomy
    a classification of organisms based on similarities
  163. thallus
    a plant body without true stems or roots or leaves or vascular system; characteristic of the thallophytes
  164. theory
    a belief that can guide behavior
  165. thorax
    the body of an arthropod between the head and the abdomen
  166. transduction
    the process whereby a transducer accepts energy in one form and gives back related energy in a different form
  167. transformation
    the act of changing in form or shape or appearance
  168. translocation
    the transport of dissolved material within a plant
  169. transpiration
    the emission of water vapor from the leaves of plants
  170. univalve
    used of mollusks, especially gastropods, as snails etc.
  171. vaccine
    injection of weakened or dead microbes to create antibodies
  172. vacuole
    a tiny cavity filled with fluid in the cytoplasm of a cell
  173. ventricle
    a chamber of the heart that receives blood from an atrium
  174. virus
    infectious agent that replicates itself within living hosts
  175. watershed
    a ridge of land that separates two adjacent river systems
  176. xylem
    plant tissue that conducts water and dissolved nutrients
  177. zooplankton
    animal constituent of plankton
  178. zygospore
    a plant spore formed by two similar sexual cells
  179. zygote
    the cell from the union of a haploid spermatozoon and ovum
Created on March 15, 2012 (updated April 5, 2012)

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